[Desktop] Medium/High/Extra High reasoning becomes unavailable or reverts to Instant in regular Chat

What version of the Codex App are you using (From “About Codex” dialog)?

26.831.21537

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64

What issue are you seeing?

After updating the Windows desktop app to the latest available version, the reasoning-effort slider no longer works correctly.

When I select Medium, High, or Extra High and release the slider, it immediately snaps back to Instant.

The behavior is:

• Instant → stays selected
• Medium → immediately snaps back to Instant
• High → immediately snaps back to Instant
• Extra High → immediately snaps back to Instant
• Pro → stays selected

My Pro usage allowance is currently exhausted, so in practice the Windows desktop app leaves me with only Instant as a usable selectable mode.

This issue occurs only in the Windows desktop app.

Using the exact same ChatGPT Pro account:

• ChatGPT on the web works correctly.
• The mobile ChatGPT app works correctly.
• Medium, High, and Extra High can all be selected normally on web and mobile.

The problem started immediately after a Windows desktop app update. The slider worked normally before that update.

I have already uninstalled and reinstalled the Windows desktop app using the latest available version, but the issue remains unchanged.

I have attached a screen recording showing the problem. In the recording, Medium, High, and Extra High visibly snap back to Instant as soon as the slider is released.

https://github.com/user-attachments/assets/03b10a36-16f6-4992-9240-19ff0d95bc1d

I cannot determine whether this is only a UI/state synchronization bug or whether the actual reasoning effort sent to the backend is also being reset to Instant. Responses can still show some reasoning behavior even when the UI has returned to Instant, so I do not want to assume which layer is failing.

What steps can reproduce the bug?

1. Open the ChatGPT/Codex Windows desktop app on Windows 10.
2. Sign in with my ChatGPT Pro account.
3. Start a new chat.
4. Open the reasoning/model selector.
5. Drag the reasoning-effort slider from Instant to Medium.
6. Release the slider.
7. Observe that it immediately snaps back to Instant.
8. Repeat with High.
9. Observe that it immediately snaps back to Instant.
10. Repeat with Extra High.
11. Observe that it immediately snaps back to Instant.
12. Select Pro.
13. Observe that Pro stays selected instead of snapping back.

The issue is consistently reproducible.

Additional comparison:

1. Sign in to chatgpt.com with the same account.
2. Select Medium, High, or Extra High.
3. All of these settings remain selected normally.
4. Repeat the same test in the mobile ChatGPT app.
5. All of these settings also work normally there.

Troubleshooting already performed:

• Confirmed that the Windows desktop app is already on the latest version available to me.
• Completely uninstalled the Windows desktop app.
• Reinstalled the latest version.
• Signed back into the same account.
• Tested again in a new conversation.
• The behavior remained exactly the same after reinstalling.

The issue began only after updating the Windows desktop app. It did not occur on the previous version.

A screen recording demonstrating the reproduction is attached to this issue.

What is the expected behavior?

Medium, High, and Extra High should remain selected after I choose them, just as they do when using the same ChatGPT Pro account on the web and mobile apps.

Selecting a reasoning-effort level should not automatically reset the selector to Instant.

If a particular reasoning level is unavailable because of an account limit or another restriction, the app should explicitly indicate that state rather than silently moving the selector back to Instant.

The Windows desktop app should behave consistently with the web and mobile clients for the same account and available reasoning modes.

Additional information

This appears to be specific to the Windows desktop client rather than my ChatGPT account.

Important observations:

• OS: Windows 10
• Subscription: ChatGPT Pro
• The issue started immediately after updating the desktop app.
• The previous desktop app version did not have this problem.
• The current version is the latest version available to me.
• Uninstalling and reinstalling the application did not resolve the issue.
• The same account works correctly on chatgpt.com.
• The same account works correctly in the mobile ChatGPT app.
• Only the Windows desktop app exhibits the problem.
• Medium, High, and Extra High all snap back to Instant.
• Pro remains selected normally, although my current Pro usage allowance is exhausted.
• The behavior is consistently reproducible in new chats.
• A screen recording is attached showing the selector behavior.

Because the same account and reasoning options work correctly on other clients, this may be a Windows-specific regression involving the reasoning selector, client-side state, entitlement synchronization, or reasoning-effort routing.

I am specifically reporting the selector behavior and am not claiming that the backend definitely uses Instant after the UI snaps back, because I do not have a reliable way to verify the reasoning effort actually sent by the Windows client.

This started only after the desktop app update, which may help narrow down the regression.

Additional reproduction result that may help narrow this down:

I tested the same account on a separate laptop that had never had the ChatGPT desktop app installed before.

After installing the desktop app for the first time and signing in with my account, the exact same issue occurred immediately: Medium, High, and Extra High snap back to Instant.

This strongly suggests that the problem is not caused by corrupted local app data, cached state, a previous installation, or leftover configuration on my original PC.

The issue follows the account across separate Windows machines, including a completely fresh ChatGPT desktop installation, while the same account continues to work normally on the web and mobile clients.

This may indicate an account-level entitlement / feature-flag / quota state that is being handled incorrectly specifically by the desktop client.

Start by reproducing the reasoning-effort selector failure in the Windows desktop app on a fresh installation, using the listed Medium, High, Extra High, and Pro steps. Compare the desktop behavior with web and mobile, then trace whether the reset is in selector state, entitlement handling, or routing. Done means supported levels remain selected, while unavailable levels are clearly reported instead of silently reverting to Instant.